Effect of Practice Structure and Feedback Frequency on Voice Motor Learning in Older Adults

The long-term goal of this research is to advance the rehabilitation of voice disorders through the study and development of efficacious treatment regimes based upon motor learning principles. This study examined the effect of contextual interference (CI) of practice structure with knowledge of results (KR) feedback on motor learning of a novel voice task, "Twang," by hypophonic, novice, and expert older adults.

Prospective, randomized controlled mixed design.

A total of 92 adults, age 55-80, recruited from the following motor skill levels: 1) Hypophonic voice; 2) Novice-untrained vocalists; 3) Expert-trained vocalists were randomly assigned to four different interventions and examined during acquisition, retention, and transfer phases of motor learning. Participants from each skill-level practiced the novel task, "Twang," according to the randomly assigned Practice Structure/KR combinations: 1) Blocked practice/100%KR; 2) Blocked practice/55% KR; 3) Random practice/100%KR; 4) Random practice/55% KR.

During the motor performance phase, our results mirrored those reported in the limb motor learning literature for CI: A Blocked practice structure enhanced short-term effects of motor acquisition for novice, expert, and hypophonic subjects. The only significant result for KR occurred when paired with Random Practice in the hypophonic subject group: 100% KR paired with Blocked practice increased motor performance, but degraded motor learning.

Fundamental motor learning principles were explored within the context of a voice training paradigm. Practice with a high CI and low frequency of KR degraded performance during short-term acquisition but enhanced long-term performance effects of motor learning. Voice clinicians and teachers may benefit by implementing motor learning theory into practice during training and treatment sessions.